1. Field of the Invention
The present invention relates to methods and apparatus for incubating and hatching eggs and more particularly to such methods and apparatus in which heat generated from living embryos and built up in an enclosed environment is transferred out of the environment so that optimum conditions can be maintained.
2. Description of the Related Art
Egg hatcheries in which environmental conditions are controlled to optimize the number of hatched eggs and/or properly maintain hatched chicks are known in the art. The primary concerns for operating an incubator or hatchery are maintaining the ambient air around the incubator/hatchery chamber at an optimum temperature of 70.degree. F. and temperatures within the chamber of around 99.degree. F. Other concerns include maintaining the proper humidity and mixture of gases within the hatchery chamber. Unfortunately, living embryos within the incubator or hatcher produce heat that interferes with the careful environmental equilibrium established in the enclosed system. Accordingly, environmental control apparatuses have been developed especially for the hatchery/incubator market in response to these concerns.
One of the most successful designs is described in applicant's own U.S. Pat. No. 5,025,619 in which hot and cold water are circulated through coils under the control of microprocessor means responsive to conditions within the hatchery chamber to either raise or lower the temperature for optimum conditions. Heat is exchanged between the ambient air and the water filled coils thus regulating the temperature of the chamber.
Water-based heating and cooling systems, including applicant's own, have several drawbacks. It has been found, for instance, that the efficiency of this system is reduced over time by the build-up on all exposed surfaces of down from chick feathers. This is especially pronounced on the cool water coils where down sticks to the condensate formed on the coils. A by-product of this phenomenon makes the coils drip, thus causing wet floors and wet down which can harbor bacteria. Additionally, water-based cooling systems tend to dry out the air within the chamber thus forming the need for a separate humidity control device within the chamber. Finally, such systems tend to be complicated, expensive, and difficult to recover wasted heat.
Air has been used as a medium for temperature control but this has been primarily limited to simply dumping quantities of cooled or heated air into the hatchery/incubator chamber. This has the drawback of changing the gas mixture within the chamber which is bad for the newly hatching chicks.
Accordingly, a need remains for an improved system for regulating the temperature within a hatchery/incubator chamber that avoids the drawbacks of the prior art.